People have been leaving for NZ and Aus for decades BUT previously we could attract 1st world HCP's back here.... now thats harder, why would you want to become a UK citizen but then not have family FOM/Erasmus/etc with the EU?
Remember the overseas nurses that looked after Bojo, left the UK not long after, stating stress.
The tragedy is that its UK tax payers providing the facilities for professional people to train/get experience and often thats far more than the tuition fees but other countries getting the benefit.
As more leave, so more will line up behind them.
Or as one consultant put it "if you don't keep the junior doctors, then we wont get the consultants for tomorrow's NHS"
Like everything in this country... short term rules :(